1. Field of the Invention
This invention relates to an improved condition responsive valve construction and method of making the same.
2. Prior Art Statement
It is known to provide a valve construction having a housing means provided with a chamber and port means leading to the chamber and having an axially movable piston means disposed in the chamber to interconnect certain of the port means together in relation to the axial position of the piston means that is caused by a condition responsive device operatively associated with the piston means.
For example, see the following four U.S. patents:
(1) U.S. Pat. No. 3,989,059--Jackson et al PA1 (2) U.S. Pat. No. 3,960,125--Payne PA1 (3) U.S. Pat. No. 3,972,472--Kawabata PA1 (4) U.S. Pat. No. 3,364,942--Ney et al PA1 (5) U.S. Pat. No. 4,147,180--Steele, Jr.
It appears that the valve construction of item (1) above has an axially movable piston member which through the length thereof can control various sets of ports in the housing means carrying the piston member, the piston member being operated by a piston and cylinder temperature responsive device operatively interconnected to one end of the piston member.
Similarly, the valve construction of item (2) above has a piston member for controlling port means of a housing means, the piston member of item (2) above carrying axially spaced flexible O-rings in annular grooves thereof to provide the sealing functions between certain ports thereof whereas the housing means of item (1) above has such O-rings being carried thereby to operate on various lands of the piston member.
It appears that the valve construction of item (3) above has a single disc-like piston member acting against a plurality of non-attached piston-like valve stems carried respectively by a plurality of piston-like valve members that control separate sets of port means of a housing means in response to sensed temperature of a temperature responsive device interconnected to the disc-like piston member.
It appears that the valve construction of item (4) above has a pair of piston-like valve members disposed for parallel axial movement in a housing, the piston valve members having adjacent ends thereof interconnected together outboard of the housing means receiving the same.
It is also known to provide a self-contained temperature responsive valve construction having a housing provided with a pair of ports separated by a valve seat that is opened and closed by a valve member in response to the temperature sensed by a piston and cylinder type temperature responsive device carried by the housing and being operatively associated with the valve member to control the same through axial movement thereof, a by-pass passage being adapted to interconnect the pair of ports together independently of the valve seat and having a one-way check valve therein to permit fluid flow between the ports through the by-pass passage in only one direction. In addition, such prior known self-contained temperature responsive valve construction has restriction means always interconnecting the two ports together independently of the valve seat and one-way check valve.
For example, see the following U.S. patent:
It appears that the by-pass passage of the valve construction of item (5) above is in the piston valve member and the one-way check valve means comprises a ball member at the free end of the piston valve member.
It is also known to applicant that others have used an umbrella-type flexible one-way valve member in place of the ball valve member of the valve construction of item (5) above, the umbrella-type one-way valve member having a porous restrictor in the center thereof to provide a controlled bleed through the by-pass passage whereby such umbrella-type one-way valve member and its restrictor means is substantially identical to the one-way device illustrated in FIGS. 9-18 of the drawings of this application.